
/* Copyright (c) Mark J. Kilgard, 1994. */

/* This program is freely distributable without licensing fees
   and is provided without guarantee or warrantee expressed or
   implied. This program is -not- in the public domain. */

#include <GL/glut.h>
#include <stdio.h>

#define GAP 10

int main_w, w1, w2, w3, w4;

void
display(void)
{
	glClear(GL_COLOR_BUFFER_BIT);
	glFlush();
}

void
vis(int visState)
{
	printf("VIS: win=%d, v=%d\n", glutGetWindow(), visState);
}

void
reshape(int w, int h)
{
	int width = 50;
	int height = 50;

	glViewport(0, 0, w, h);
	if (w > 50) {
		width = (w - 3 * GAP) / 2;
	} else {
		width = 10;
	}
	if (h > 50) {
		height = (h - 3 * GAP) / 2;
	} else {
		height = 10;
	}
	glutSetWindow(w1);
	glutPositionWindow(GAP, GAP);
	glutReshapeWindow(width, height);
	glutSetWindow(w2);
	glutPositionWindow(GAP + width + GAP, GAP);
	glutReshapeWindow(width, height);
	glutSetWindow(w3);
	glutPositionWindow(GAP, GAP + height + GAP);
	glutReshapeWindow(width, height);
	glutSetWindow(w4);
	glutPositionWindow(GAP + width + GAP, GAP + height + GAP);
	glutReshapeWindow(width, height);
}

int
main(int argc, char **argv)
{
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_RGB);
	glutInitWindowSize(210, 210);
	main_w = glutCreateWindow("4 subwindows");
	glutDisplayFunc(display);
	glutVisibilityFunc(vis);
	glutReshapeFunc(reshape);
	glClearColor(1.0, 1.0, 1.0, 1.0);
	w1 = glutCreateSubWindow(main_w, 10, 10, 90, 90);
	glutDisplayFunc(display);
	glutVisibilityFunc(vis);
	glClearColor(1.0, 0.0, 0.0, 1.0);
	w2 = glutCreateSubWindow(main_w, 110, 10, 90, 90);
	glutDisplayFunc(display);
	glutVisibilityFunc(vis);
	glClearColor(0.0, 1.0, 0.0, 1.0);
	w3 = glutCreateSubWindow(main_w, 10, 110, 90, 90);
	glutDisplayFunc(display);
	glutVisibilityFunc(vis);
	glClearColor(0.0, 0.0, 1.0, 1.0);
	w4 = glutCreateSubWindow(main_w, 110, 110, 90, 90);
	glutDisplayFunc(display);
	glutVisibilityFunc(vis);
	glClearColor(1.0, 1.0, 0.0, 1.0);
	glutMainLoop();
	return 0;             /* ANSI C requires main to return int. */
}
